Cartridge



L. RINGDAL Dec. 29, 1959 *,ggggggg CARTRIDGE INVENTOR LARS RINGDAL United The present invention relates to a cartridge of the kind comprising a base having a tubular extension and a case Which consists of relatively elastic flexible synthetic resin material, such as polyethylene or polyvinylchloride, and which tightly encloses the tubular extension, the attachment of the vcase and cartridge base to each other being suitably secured by means of a bead on the one member in engagement with a corresponding groove in the other member.

For obtaining a satisfactory moulding of a cartridge case of this kind, the walls of the case must be as thin as possible. If the case' is moulded with a too thick wall, the case contracts so much during the moulding that exact dimensions are diicult to obtain. On the other hand the case, especially over that part of its length which corresponds to the length of the chamber of the rearm, is subjected to so great mechanical stresses, especially when the cartridge ease is introduced and ejected, that the said portion of the cartridge must have sutlcient strength and rigidity.

The invention has for its object to meet both the requirements above mentioned. With this object in view and according to the invention a second case also of thermoplastic synthetic resin material is provided internally of the irst said case in tight engagement with both the case and the tubular extension of the cartridge base. The inner case has-suitably the same length as the length of the chamber of the firearm.

The material of the inner case should also be elastic, but may advantageously be harder than the material of the outer case.

By letting the inner case be closed at the front end, it is besides obtained that the powder is prevented from penetrating to the front end of the outer case, so that ignition of the powder and the ring of the shot take place in a faultless manner.

A longitudinal section of an embodiment of a cartridge according to the invention is illustrated in the drawing.

The figure shows the cartridge made as a blank cartridge. 1 designates the cartridge case proper, which is produced from soft, elastic synthetic resin material, such as polyethylene or polyvinylchloride. 2 designates the cartridge base which may consist of a suitable metal and in which the percussion cap 3 is secured. 4 designates a circumferential groove in which the ejector member of the firearm is intended to engage.

The tubular extension of the cartridge base is designated 5, and has two radially projecting beads or collars 6, which engage in corresponding grooves on the inner face of the case 1. Hereby a secure attachment of the said members to each other is obtained with the assistance of the elasticity of the material of the case 1.

For use as blank ammunition the case 1 is at the front end provided with score lines 7 which are arranged in such a waypreferably crossing each other in the centerthat the front end of the case when the shot is red, opens through soft, elastic spreading-out of the aps provided by the score lines and so that no splinters are produced.

Internally of the case 1 and in tight engagement with the inner face of the case and the inner face of the tubular extension 5, according to the invention a second case 8 is provided, also of synthetic resin material, which suitably may be elastic but which with advantage has a higher degree of hardness than the material of the case 1.

In the embodiment shown also the inner case, for the' purposes described, is closed at the front end and made as a blank cartridge case, the inner case having similar to the case 1 at the front end score lines 9 of the same kind as the score lines 7.

In the embodiment according to the linvention a unitary cartridge is obtained, which may be used to equal advantage both in ordinary guns and in automatic firearms.

Even if the invention is shown and described in connection with a blank cartridge, it will be understood that the same can be adapted also for use in a live cartridge.

I claim:

1. A cartridge comprising a cartridge base having a tubular extension, a rst case of relatively elastic flexible synthetic resin material having a rear chamber tightly enclosing said tubular extension at one end of said case and a second synthetic resin case of shorter length than said rst case having one open end and containing powder, said second case being located internally of said irst case in tight engagement therewith and with said tubular extension about the open end thereof, said second case preventing said powder from sliding to the front end of said iirst case thereby promoting an ecient ignition of said powder and protecting said powder from atmospheric influences.

2. A cartridge as set forth in claim 1 wherein said` second case has a length substantially corresponding to the length of said chamber of said cartridge.

3. A cartridge as set forth in claim 1 wherein the material of said second case has a higher degree of hardness than the material of said first case.

4. A cartridge as set forth in claim 1 wherein said Ist and second cases are constructed of polyethylene.

5. A cartridge as set forth in claim 1 wherein said rst and second cases are constructed of polyvinylchloride.

6. A cartridge comprising a cartridge base having a tubular extension, a irst case closed at one end of relatively elastic exible synthetic resin material tightly enclosing at its other end said tubular extension externally, a second case of shorter length than said iirst case containing powder also of a synthetic resin material located internally of said rst case in tight engagement therewith and with said tubular extension internally, said second case being closed at its front end preventing said powder from sliding to the front end of said first case, said closure provided with score lines at such front end thereby promoting an efficient ignition of said powder and protecting said powder from atmospheric influences.

7. A cartridge as set forth in claim 6 wherein said rst case is provided with score lines at such front end.

References Cited in the le of this patent UNITED STATES PATENTS A97,615 Slatcher Dec. 7, 1869 352,125 Graydon Nov. 9, 1886 392,922 Johnson Nov. 13, 1888 1,233,071 Lindquist Iuly 10, 1917 2,686,936 Tuckerman et al Aug. 24, 1954 FOREIGN PATENTS 7,193 Great Britain of 1891 74,314 Germany Apr. 5, 1894 394,037 Great Britain June 22, 1933 238,162 Switzerland Oct. l, 1945 522,888 Belgium Oct. 15, 1953 732,633 Great Britain June 29, 1955 OTHER REFERENCES Publication, Product Engineering, March 1944, Properties of Polyethylene. (Copy in Div. 10.) 

